How much do you know about ductile iron pipes?

We cannot live without water in our lives, whether it is for drinking or for use, the most common one is tap water. I wonder if you have ever thought about the transportation of tap water. So, what is the main material of tap water pipes? What characteristics does it have to ensure the safety of water quality and transportation? It is the subject to be introduced today-ductile iron pipes.

Ductile iron pipes are made of cast iron water above No. 18, after adding spheroidizing agent, and then cast by high-speed centrifugation of centrifugal ductile iron machine. They are referred to as ductile pipes, ductile iron pipes and ductile cast pipes, etc. Their main components are carbon, silicon, manganese, sulfur, phosphorus and magnesium. Ductile iron pipes are also ideal materials for tap water pipes, and their main use is naturally to transport tap water.

In many areas of my country, the connection between medium and small diameter pipes of ductile iron pipes mainly adopts bearing or flange interface methods; and ductile iron, the allowable restricted corners must have absolute seismic resistance and sealing.

Characteristics of ductile iron pipe:

Ductile iron pipe is a kind of cast iron pipe. In terms of quality, the spheroidization level of cast iron pipe is controlled to level 1-3, that is, the spheroidization rate is not less than 80%, so the mechanical properties of ductile iron pipe material itself can be improved relatively well, so that it has the essence of iron and the performance of steel. After annealing, the metallographic structure of ductile iron pipe is ferrite plus a small amount of pearlite, which makes it have good mechanical properties, excellent anti-corrosion performance, good ductility, good sealing effect, and easy installation. In addition, in medium and low pressure pipe networks, ductile iron pipes have the advantages of safe and reliable operation, low breakage rate, convenient construction and maintenance, and excellent anti-corrosion performance.

But there are also some disadvantages: for example, in high-pressure pipe networks, the pressure resistance is low, so it is generally not used; the pipe body is relatively bulky, so machinery must be used during installation; if there is a leak after the pressure test, all pipes must be dug out, and then the pipes must be lifted to a height that can be put into the clamp, and the clamp must be installed to prevent leakage.

Appearance performance of ductile iron pipe: Ductile iron pipe is called centrifugal ductile iron pipe. It is mainly used for water supply, gas transmission, oil transmission and other work in municipal and industrial and mining enterprises. It is the first choice for water supply pipeline materials, so it has a high cost performance. Anti-corrosion treatment of ductile iron pipe. Mainly includes the following methods:

1. Coating with asphalt paint. This method is suitable for pipelines that transport gas. Moreover, preheating the pipe before painting can improve the adhesion of asphalt paint, thereby accelerating drying.

2. Use cement mortar lining plus special coating. This method is suitable for pipelines that transport sewage and can improve the corrosion resistance of the lining.

3. Use epoxy coal tar coating. This method is suitable for both gas pipelines and sewage pipelines. The coating has high adhesion and a very smooth surface.

4. Use epoxy ceramic lining. This method is suitable for sewage pipelines and gas pipelines. However, its manufacturing process is difficult and costly, so it has certain limitations in use. Epoxy ceramic lining is an excellent anti-corrosion coating with high adhesion and finish.

5. Use aluminate cement coating or sulfate cement coating. This method is suitable for the internal corrosion protection of ductile iron pipes used in sewage pipes, which can improve the ability to resist the corrosion of acid and alkali components in sewage.

6. Use polyurethane coating, which is a new type of green special coating developed to meet environmental protection needs, with good wear resistance and corrosion resistance.